Methods of processing digital image and/or video data including luminance filtering based on chrominance data and related systems and computer program products

Abstract

Digital image and/or video data is processed wherein a frame of the data comprises a plurality of rows and columns of pixels with data for each pixel including a luminance value and a chrominance value. Chrominance values and luminance values may be received for a current pixel and at least one adjacent pixel, and the chrominance values of the current pixel and the at least one adjacent pixel may be compared. The luminance value of the current pixel may be filtered wherein a strength of filtering the luminance value is based on the comparison of the chrominance values of the current and at least one adjacent pixels.

1 . A method for processing digital image and/or video data wherein a frame of the data comprises a plurality of rows and columns of pixels with data for each pixel including a luminance value and a chrominance value, the method comprising: 
 receiving chrominance values and luminance values for a current pixel and at least one adjacent pixel;    comparing the chrominance values of the current pixel and the at least one adjacent pixel; and    filtering the luminance value of the current pixel wherein a strength of filtering the luminance value is based on the comparison of the chrominance values of the current and at least one adjacent pixels.    
     
     
         2 . A method according to  claim 1  wherein filtering the luminance value of the current pixel comprises averaging the luminance value of the current pixel with a luminance value of at least one adjacent pixel.  
     
     
         3 . A method according to  claim 2  wherein a strength of the filtering is determined by weightings applied to the luminance values when averaging the luminance values.  
     
     
         4 . A method according to  claim 1  wherein comparing the chrominance values of the current and adjacent pixels comprises calculating a difference between the chrominance values of the current and adjacent pixels.  
     
     
         5 . A method according to  claim 4  further comprising: 
 reducing the strength of filtering when the difference between the chrominance values of the current and adjacent pixels is above a predetermined threshold; and    increasing the strength of filtering when the difference between the chrominance values of the current and adjacent pixels is below the predetermined threshold.    
     
     
         6 . A method according to  claim 4  wherein the data is provided in a YCrCb format where Y is a luminance value and Cr and Cb are respective red and blue chrominance values for each pixel.  
     
     
         7 . A method according to  claim 6  wherein comparing the chrominance values of the current and adjacent pixels comprises summing an absolute value of a difference of the Cr value for each pixel and an absolute value of a difference of the Cb value for each pixel.  
     
     
         8 . A method according to  claim 7  wherein the absolute value of the difference of the Cr value for each pixel comprises a squared difference of the Cr values and wherein the absolute value of the difference of the Cb value for each pixel comprises a squared difference of the Cb values.  
     
     
         9 . A method according to  claim 5  wherein decreasing the strength of filtering comprises passing the luminance data for the pixel without filtering.  
     
     
         10 . A method according to  claim 1  further comprising: 
 before filtering the luminance value of the current pixel, comparing the luminance values of the current pixel and at least one adjacent pixel, wherein a strength of the filtering is based on the comparison of the chrominance values of the current pixel and at least one adjacent pixel and on the comparison of the luminance values.    
     
     
         11 . A method according to  claim 1  wherein receiving the chrominance values and luminance values for a current pixel and at least one adjacent pixel comprises receiving the chrominance and luminance values from a digital camera, the method further comprising: 
 encoding the data including the filtered luminance value; and    transmitting the encoded data.    
     
     
         12 . A method according to  claim 11  wherein encoding comprises varying a rate of compression of the data and wherein a strength of the filtering is based on the comparison of the chrominance values of the first and second pixels and on the rate of compression applied during encoding.  
     
     
         13 . A method according to  claim 11  wherein receiving chrominance values and luminance values from the digital camera comprises receiving chrominance values and luminance values for a frame of data and wherein filtering the luminance value comprises filtering luminance values for the frame of data, the method further comprising: 
 identifying portions of the filtered frame to which texture should be applied; and    transmitting an identification of portions of the frame to which texture should be applied.    
     
     
         14 . A method according to  claim 13  further comprising: 
 transmitting an identification of one of a plurality of textures which should be applied.    
     
     
         15 . A method according to  claim 1  further comprising: 
 receiving encoded data; and    before receiving the chrominance values and luminance values for the current pixel and the at least one adjacent pixel, decoding the encoded data to provide the chrominance values and luminance values for the current pixel and for the at least one adjacent pixel.    
     
     
         16 . A method according to  claim 15  wherein filtering the luminance value comprises filtering luminance values for a frame of data, the method further comprising: 
 identifying a portion of the frame to which texture should be applied; and    after filtering the luminance values from the frame of data, applying the texture to the identified portions of the frame.    
     
     
         17 . A method according to  claim 1  wherein the first and adjacent pixels are one of horizontally adjacent, vertically adjacent, diagonally adjacent, temporally adjacent, and/or non-immediately adjacent.  
     
     
         18 . A method according to  claim 1  wherein filtering the luminance value of the current pixel comprises low-pass filtering the luminance value of the current pixel.  
     
     
         19 . A method of processing digital image and/or video data from a transmitting device wherein a frame of the data comprises a plurality of rows and columns of pixels with data for each pixel including a luminance value and a chrominance value, wherein the data is pre-filtered and encoded before transmission and wherein the data is pre-filtered according to a pre-filtering algorithm, the method comprising: 
 receiving the pre-filtered and encoded data from the transmitting device;    decoding the pre-filtered and encoded data from the transmitting device; and    post-filtering the decoded data according to a post-filtering algorithm wherein the pre-filtering and post-filtering algorithms are matched.    
     
     
         20 . A method according to  claim 19  wherein parameters of the pre-filtering algorithm are transmitted from the transmitting device, the method further comprising: 
 receiving the parameters of the pre-filtering algorithm transmitted from the transmitting device wherein operation of the post-filtering algorithm is adapted according to the parameters of the pre-filtering algorithm received form the transmitting device.    
     
     
         21 . A method according to  claim 20  wherein the parameters of the pre-filtering algorithm transmitted from the transmitting device comprise filtering strengths applied by the pre-filtering algorithm to luminance values of the data and wherein a strength of post-filtering is adapted in accordance with filter strengths applied by the pre-filtering algorithm.  
     
     
         22 . A method according to  claim 20  wherein the parameters of the pre-filtering algorithm transmitted from the transmitting device comprise an identification of the pre-filtering algorithm and wherein the post-filtering algorithm is adapted to match the pre-filtering algorithm responsive to receiving the identification of the pre-filtering algorithm.  
     
     
         23 . A method according to  claim 19  wherein each of the pre-filtering and post-filtering algorithms compare chrominance values of a current pixel and at least one adjacent pixel and filter a luminance value of the current pixel such that a strength of the filtering of the luminance value of the current pixel is based on the comparison of the chrominance values of the current pixel and the at least one adjacent pixel.  
     
     
         24 . A method of processing digital image and/or video data from a transmitting device wherein a frame of the data comprises a plurality of rows and columns of pixels with data for each pixel including a luminance value and a chrominance value, wherein the data is pre-filtered and encoded before transmission, wherein the data is pre-filtered according to a pre-filtering algorithm, and wherein parameters of the pre-filtering algorithm are transmitted from the transmitting device, the method comprising: 
 receiving the pre-filtered and encoded data from the transmitting device;    receiving the parameters of the pre-filtering algorithm transmitted from the transmitting device;    decoding the pre-filtered and encoded data from the transmitting device; and    post-filtering the decoded data according to a post-filtering algorithm wherein the operation of the post-filtering algorithm is adapted according to the parameters of the pre-filtering algorithm received from the transmitting device.    
     
     
         25 . A method according to  claim 24  wherein the pre-filtering and post-filtering algorithms are matched.  
     
     
         26 . A method according to  claim 24  wherein each of the pre-filtering and post-filtering algorithms compare chrominance values of a current pixel and at least one adjacent pixel and filter a luminance value of the current pixel such that a strength of the filtering of the luminance value of the current pixel is based on the comparison of the chrominance values of the current pixel and the at least one adjacent pixel.  
     
     
         27 . A method according to  claim 24  wherein the parameters of the pre-filtering algorithm transmitted from the transmitting device comprise filtering strengths applied by the pre-filtering algorithm to luminance values of the data and wherein a strength of the post-filtering is adapted in accordance with filter strengths applied by the pre-filtering algorithm.  
     
     
         28 . A method according to  claim 24  wherein the parameters of the pre-filtering algorithm transmitted from the transmitting device comprise an identification of the pre-filtering algorithm and wherein the post-filtering algorithm is adapted to match the pre-filtering algorithm responsive to receiving the identification of the pre-filtering algorithm.  
     
     
         29 . A method for processing digital image and/or video data wherein a frame of the data comprises a plurality of rows and columns of pixels, the method comprising: 
 receiving a luminance value for a current pixel;    filtering the luminance value of the current pixel; and    encoding the data including the filtered luminance value wherein encoding data comprises varying a rate of compression of the data, and wherein a strength of the filtering of the luminance value is varied responsive to the rate of compression applied during encoding.    
     
     
         30 . A method according to  claim 29  wherein receiving further comprises receiving a chrominance value for the current pixel and receiving a luminance and chrominance value for at least one adjacent pixel, the method further comprising: 
 comparing the chrominance values of the current pixel and the at least one adjacent pixel, wherein the strength of filtering the luminance value is further based on the comparison of the chrominance values of the current and at least one adjacent pixel.    
     
     
         31 . A method according to  claim 29  further comprising: 
 transmitting the encoded data including the filtered luminance value over a wireless interface.    
     
     
         32 . A method according to  claim 29  wherein filtering the luminance value of the current pixel comprises averaging the luminance value of the current pixel with a luminance value of at least one adjacent pixel.  
     
     
         33 . A method according to  claim 32  wherein a strength of filtering is determined by weightings applied to the luminance values when averaging the luminance values.  
     
     
         34 . A method according to  claim 29  further comprising: 
 increasing the strength of filtering responsive to a relatively high rate of compression applied during encoding; and    decreasing the strength of filtering responsive to a relatively low rate of compression applied during encoding.    
     
     
         35 . A method for processing digital image and/or video data wherein a frame of the data comprises a plurality of rows and columns of pixels, the method comprising: 
 receiving data for pixels of a frame;    filtering the data for the pixels of the frame;    identifying a portion of the frame of data to which texture should be applied;    encoding the filtered data for the pixels of the frame;    transmitting the encoded and filtered data for the pixels of the frame; and    transmitting identification of the portion of the frame of data to which texture should be applied.    
     
     
         36 . A method according to  claim 35  further comprising: 
 providing a characterization of the texture to be applied to the identified portion of the frame; and    transmitting the characterization of the texture to be applied to the identified portion of the frame.    
     
     
         37 . A method according to  claim 36  wherein providing a characterization of the texture comprises identifying one of a plurality of predetermined textures.  
     
     
         38 . A method according to  claim 35  wherein identifying a portion of the frame of data to which texture should be applied comprises comparing the filtered data for the pixels of the frame with the unfiltered data for the pixels of the frame of the data and identifying the portion of the frame of data to which texture should be applied based on comparing the filtered data and unfiltered data for the frame.  
     
     
         39 . A method according to  claim 35  wherein the data for the pixels of the frame comprises luminance values and chrominance values and wherein identifying a portion of the frame of data to which texture should be applied comprises identifying pixels having similar chrominance values.  
     
     
         40 . A method according to  claim 35  wherein the data for the pixels of the frame comprises luminance values and chrominance values, and wherein the texture comprises a variation of luminance values included in identified portions of the frame to which the texture should be applied.  
     
     
         41 . A method according to  claim 35  wherein the data for the pixels of the frame comprises luminance values and chrominance values, and wherein filtering the data for the pixels of the frame comprises: 
 receiving chrominance values and luminance values for a current pixel and at least one adjacent pixel;    comparing the chrominance values of the current pixel and the at least one adjacent pixel; and    filtering the luminance value of the current pixel wherein a strength of the filtering the luminance value is based on the comparison of the chrominance values of the current and at least one adjacent pixels.    
     
     
         42 . A method according to  claim 35  wherein receiving data for pixels of a frame of the data comprises receiving the data from a digital camera.  
     
     
         43 . A method for processing digital image and/or video data wherein a frame of the data comprises a plurality of rows and columns of pixels, the method comprising: 
 receiving data for pixels of a frame of the data;    decoding the data for pixels of the frame;    identifying a portion of the frame of data to which texture should be applied; and    after decoding the data for the pixels of the frame, applying the texture to the identified portion of the frame of data.    
     
     
         44 . A method according to  claim 43  further comprising: 
 receiving a characterization of the texture to be applied to the identified portion of the frame wherein applying the texture to the identified portion of the frame comprises applying the texture according to the received characterization.    
     
     
         45 . A method according to  claim 44  wherein the characterization identifies one of a plurality of predetermined textures.  
     
     
         46 . A method according to  claim 43  wherein the data for the pixels of the frame comprises luminance values and chrominance values and wherein identifying a portion of the frame of data to which texture should be applied comprises identifying pixels having similar chrominance values.  
     
     
         47 . A method according to  claim 43  wherein the data for the pixels of the frame comprises luminance values and chrominance values, and wherein the texture comprises a variation of luminance values of pixels included in identified portions of the frame to which the texture is applied.  
     
     
         48 . A method according to  claim 43  further comprising: 
 before applying the texture, filtering the decoded data for the pixels of the frame.    
     
     
         49 . A method according to  claim 43  wherein receiving data for pixels of a frame of the data comprises receiving the data over a wireless interface.